Research plots have demonstrated that using grits does not control fire ants. The theory behind the use of grits as a fire ant control is that the ants will eat the grits, which swell in their stomachs causing them to explode. However, fire ant workers can't eat solid food. The only member of the fire ant colony that can digest solid food is the fourth instar larval stage, which turns all solid food into a liquid form for the rest of the colony to use. Therefore, this theory is not possible.
This idea may have its origin in the fact that defatted corn grit is used as a carrier for most of the fire ant bait products. However, baits also contain various active ingredients (poisons) that control the fire ant colony.
See also FAQ #1107, "Are there any home remedies that will kill fire ants?"
